If you are using resin tooling, I cant see there is much need for machining?
Obviously very high numbers of parts, or extreme accuracy in an industrial production process, would require metal tooling, but maybe thats not really applicable to someone wanting to make small numbers of cosmetic motorcycle parts on a cost effective basis?
Maybe the force in the press is high enough to collapse bubbles.
Yep, your tools have to be perfectly matched and allow for the thickness of the lay up. I won’t mess with that stuff for now, i’d have so much time and money into machining the molds it wouldn’t pay to do it that way. I wouldn’t want to try and make FRP molds that way… would be way easy to break the molds.
I have never seen any frp molds used in press molding, Iam tempted to say its two much pressure for this style mold, but I could be wrong. all the press molds I have seen used machined aluminum molds that were heated. I think for what you want to do, a more cost efficient method would be light rtm, using a silicon reusable bag… the presses used for this method are very expensive and could only be justified by high volume production parts. however you can make your own cheap press by making a metal box frame around the molds and having bottle jacks between the metal frame and the mold creating pressure on the mold. however the pressure by this method is no wheres near the pressures that hydraulic presses create
I believe the gasses escape from the sides of the mold since the parts are generally small and are under extreme pressure
A supplier of mine runs a small GRP production shop, and sucessfully manufactures parts using cold press moulding, and GRP tooling…
Will ask him to send me a few pics of what they use…but dont think its very high tech though!
cool, look forward to seeing it
Have asked my supplier about producing some carbon mouldings for off-road bikes, but he didnt seem very interested, so this is probably something I might be trying myself.
Mostly these types of parts seem to be made using pre-preg, so if a less costly, and equally trouble free production process could be found, then I think it may be very lucrative.
what kind of parts are you thinking of making specifically?
Carbon fibre fuel tanks for Scorpa trials bikes…if its possible to find a cost effective production method to make these, then there is no reason other parts for far more common road bikes couldnt be made in the same way!
Sadly though here in the UK no one much seems interested in spending time and effort looking at anything that they are not familiar with, so its very very difficult getting any help with anything different.
Fuel tanks don’t sell to well here in the States. Some racers have them and maybe a very limited number of street bikes. Not something I see myself making. Trials bikes in Europe, possibly Canada though for what your doing probably. I’ll stick to street and racing sportbikes.
How do you join your two halves together for a tank? Make some sort of flange that fits inside the other half, kind of like how a lid fits on a thermos…flush?
Clasic; I don’t know whether you get a TV show called “How it’s Made” in the UK (a Canadian show), but they had a segment about how they made Ice hockey goalie masks. Anyway, after making the matched tools out of glass/polyester the part is cured in a press.Not as sophisticated as you describe,though. They wet out the fabric,place it in the mould and then place it in the press. Maybe the show is on youtube?
Thats exactly the way I have heard the cold press moulding process described! My supplier is infusing resin into his parts, but for small cosmetic motorcycle parts I cant see any need for that at all.
Seemingly as the press compresses the tools together, they vent through the joining flange. Obviously a bit of experimentation would be needed to get it working properly, but seems like it might be a very good process to manufacture small cosmetic parts, using poly resin system!
Fuel tanks for modern trials bikes are made from 2 small clam shell type mouldings, which are bonded together after they have been moulded.
Principle of making parts like this using cold press process, is exactly the same as any other motorcycle part, so if it works for the tanks, then it seems like a simple cost effective method of making any relatively simple small bike parts, cheaply and easily.